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Photos: Courtesy of Marga Ree - www.rxroots.com
From: Marga Ree
Sent: Saturday, November 19, 2005 2:42 PM
Subject: [roots] Internal bleaching
This 40 year old woman wanted to have done something on the
yellow discoloration of 2.1. She recalled sustaining a trauma
when she was 20 years of age, after which the tooth turned
yellow. No other signs or symptoms. Looking at the rad,
you can see a partial calcification in the coronal part of
the canal. At midroot level, a canal is clearly visible,
although of an irregular shape.
After some troughing I found the original canal, which was
very narrow to begin with, but which became very wide at
midroot level. There was profound bleeding upon entering
this part . It felt like a resorption defect. Apical
foramen gauged with LS # 70, and a dressing of Ca(OH)2.
Sec. session: application of an apical plug of MTA, and in
the third session I finished the RCT , and placed sodium
perborate which I changed 3 times with time intervals of
2 weeks. Before I make the build-up of composite, I soak
the access opening in 10% sodium ascorbate for a couple of
minutes, this acts as a kind of a scavenger, to eliminate
any residual oxygen, which can affect polymerization of
Here is an old case, which I treated approx 5 years ago.
I usually place a barrier of RMGIC of 2 mm on top of the
filling material (see yellow arrows), and apply this with
a needle tube. This means that the filling material should
be about 4 mm below the CEJ, so after the barrier of 2 mm
is placed, there is still 2 mm below the CEJ for the sodium
perborate to be effective. I change the sodium perborate
every 2 weeks, if necessary. After having obtained a
satisfactory result, I remove the remnants of peroxide with
the application of sodium ascorbate for a couple of minutes,
see below mentioned abstract. Then the usual acid etching,
priming and bonding for a composite build-up.
Below is a summary of Ben Schein on sodium ascorbate.
Sodium Ascorbate is a non-acidic form of Vitamin C, a major
antioxidant as well as one of the most important Vitamins
required by the Human body on a regular and ongoing basis
may assist in the treatment of colds and flu by reducing the
severity and duration of symptoms . Sodium Ascorbate is a
buffered form of Vitamin C that consists of 90% Ascorbic
Acid bound to 10% Sodium. It is sold in Nutrition Holistic
Vitamin Stores in liquid form. "Nutrition freaks"
use on a regular and ongoing basis because they think it
assists in the treatment of colds and flu by reducing the
severity and duration of symptoms - Marga
1: J Dent Res. 2002 Jul;81(7):477-81.
Reversal of compromised bonding in
Lai SC, Tay FR, Cheung GS, Mak YF, Carvalho RM, Wei SH,
Toledano M, Osorio R, Pashley DH.
Oxygen inhibits polymerization of resin-based materials. We
hypothesized that compromised bonding to bleached enamel can
be reversed with sodium ascorbate, an anti-oxidant. Sandblasted
human enamel specimens were treated with distilled water
(control) and 10% carbamide peroxide gel with or without
further treatment with 10% sodium ascorbate. They were bonded
with Single Bond (3M-ESPE) or Prime&Bond NT (Dentsply DeTrey)
and restored with a composite. Specimens were prepared for
microtensile bond testing and transmission electron microscopy
after immersion in ammoniacal silver nitrate for nanoleakage
evaluation. Bond strengths of both adhesives were reduced
after bleaching but were reversed following sodium ascorbate
treatment (P < 0.001). Resin-enamel interfaces in bleached
enamel exhibited more extensive nanoleakage in the form of isolated
silver grains and bubble-like silver deposits. Reduction of
resin-enamel bond strength in bleached etched enamel is
likely to be caused by a delayed release of oxygen that
affects the polymerization of resin components.
1: Oper Dent. 2003 Nov-Dec;28(6):825-9.
Reversal of dentin bonding to bleached teeth.
Kaya AD, Turkun M.
Many studies have shown a considerable reduction in enamel
bond strength of resin composite restorations when the bonding
procedure is carried out immediately after bleaching. These
studies claim that a certain waiting period is needed prior
to restoration to reach the original bond strength values prior
to bleaching. This study determined the effect of anti-oxidant
applications on the bond strength values of resin composites to
bleached dentin. Ninety human teeth extracted for orthodontic
purposes were used in this study. The labial surface of each
tooth was ground and flattened until dentin appeared. The polished
surfaces were subjected to nine different treatments:
1) bleaching with gel (35% Rembrandt Virtuoso)
2) bleaching with gel + 10% sodium ascorbate (SA);
3) bleaching with gel + 10% butylhydroxyanisole (BHA);
4) bleaching with sol (35% hydrogen peroxide);
5) bleaching with sol + 10% sodium ascorbate;
6) bleaching with sol + 10% BHA;
7) bleaching with gel + immersed in artificial saliva for seven
8) bleaching with sol + immersed in artificial saliva for seven
9) no treatment.
After bonding application, The resin composite in standard
dimensions was applied to all specimens. The teeth were stored
in distilled water at 37 degrees C for 24 hours and a universal
testing machine determined their resistance to shear bond strength.
The data was evaluated using ANOVA and Duncan tests. Bond strength
in the bleached dentin group significantly decreased compared to
the control group. On the other hand, the antioxidant treatment
had a reversal effect on the bond strength to dentin. After the
bleaching treatment, the 10% sodium ascorbate application was
effective in reversing bond strength. In the samples where
antioxidant was applied after the bleaching process, bonding
strength in dentin tissue was at the same level as those teeth
kept in artificial saliva for seven days.
J Oral Rehabil. 2004 Dec;31(12):1184-91.
Effect of 10% sodium ascorbate on the shear
bond strength of composite resin to bleached bovine enamel.
Turkun M, Kaya AD.
Department of Restorative Dentistry and Endodontics, School of Dentistry,
Ege University, Izmir, Turkey.
summary The purpose of this study was to comparatively investigate
the effect of antioxidant treatment and delayed bonding after
bleaching with three different concentrations of carbamide peroxide
(CP) on the shear bond strength of composite resin to enamel.
One hundred flat buccal enamel surfaces obtained from bovine
incisors were divided into three bleaching groups of 10,
16 and 22% CP (n = 30) and a control group. Each bleaching group
was then divided into three subgroups (n = 10). Group 1 consisted
of specimens bonded immediately after bleaching. Group 2 specimens
were treated with antioxidant agent, 10% sodium ascorbate, while
Group 3 specimens were immersed in artificial saliva for 1 week
after bleaching. Specimens in the control group were not bleached.
After the specimens were bonded with Clearfil SE Bond and Clearfil
AP-X, they were thermocycled and tested in shear until failure.
Fracture analysis of the bonded enamel surface was performed using
scanning electron microscope. The shear bond strength data was
subjected to one-way analysis of variance followed by Duncan's
multiple range test at a significance level of P < 0.05. Shear
bond strength of composite resin to enamel that was bonded
immediately after bleaching with 10, 16 and 22% CP was significantly
lower than that of unbleached enamel (P < 0.05). For all three
bleaching groups, when the antioxidant-treated and delayed bonding
(1 week) subgroups were compared with the control group,
no statistically significant differences in shear bond strength were
noted (P < 0.05).
Marga, I thought the whole point of
the barrier was to block from the Sodium Perborate to get to the
CEJ and cause external resorption. Why do you place a barrier at all,
if you let the Perborate into the CEJ (which may be incomplete) ?
Thomas, To my knowledge, there never has been reported an external
root resorption following bleaching with the use of sodium perborate.
Secondly, in order to get an esthetic result, you should remove any
filling material approx 2 mm below the CEJ, due to the direction of
the dentinal tubules.
My rationale for placing a barrier is that I want to prevent
leakage along the root canal filling, and I usually perform bleaching
in the same session as the obturation. But this applies to the use of
gp and sealer. You should protect the root filling, because it has not
completely set at the time of obturation. I use Resilon nowadays,
so maybe it is not necessary at all to use a barrier. I don't know,
but I guess it doesn't do any harm either. - Marga
1: J Endod. 1991 Aug;17(8):365-8.
Intracoronal isolating barriers: effect of location on root leakage and
effectiveness of bleaching agents Costas FL, Wong M.
United States Army Dental Activities, Ft. Gordon, SC.
The purpose of this study was to evaluate the ability of several
intracoronal isolating barrier materials to prevent leakage of a
bleaching agent into the roots of teeth and to determine whether
placement of the barrier material at the cementoenamel junction
or below the cementoenamel junction has an effect on the bleaching
results of the crowns. Fifty teeth were stained in vitro, and
gutta-percha fillings were placed in the root canals. The experimental
isolating barriers were placed at the cementoenamel junction or 2 mm
below the cementoenamel junction. A walking bleach of Superoxol and
sodium perborate was placed in the pulp chamber for three treatments.
The roots of the teeth were evaluated for the presence of root decoloration,
and the crowns of the teeth were evaluated for bleaching effect. Findings
from this study showed a significant difference between gutta-percha alone
and gutta-percha with barrier in preventing root decoloration (p less
than 0.05). No significant differences were found between the other
experimental groups in preventing root decoloration. Placement of
an intracoronal isolating barrier material 2 mm below the cementoenamel
junction resulted in a more acceptable esthetic bleaching result of the
crowns than did placement of barrier material at the cementoenamel junction.
For what it is worth Thomas, I have always
done it the way marga presented, although I was never aware of a resorption
issue. I did it to protect the fill and to allow for a deeper bleaching to
present excess discoloration at the cej. - gary
Prof. Rotstein, who was my specialisation
director gave us a paper explaining the barrier shouldn't be flat,
because the CEJ is higher on the M&D aspects of the roots and the
barrier should follow the CEJ.
The whole point is to prevent O2 reaching
the CEJ and causing resorption. No resorption was reported with Sodium
Perborate, but many attributed it to this barrier on the CEJ. I am not
sure there can be a problem with Sodium Perborate entering the root
filling after it's set (but who knows). Estheticly, for sure it's better
to place the Perborate bellow CEJ.- Go figure, Thomas
From: Marga Ree
Sent: Friday, February 03, 2006 6:51 PM
Subject: [roots] Internal bleaching with sodium perborate
I have posted this case earlier, but I wanted to show an example of internal
bleaching with the use of sodium perborate, I would not recommend to use
hydrogen peroxide in high a concentration, see also my response to Jeremy's
post on internal bleaching - Marga
beautiful case and results Marga - Rob
I've done this very succesfully for years
Rubber dam is mandatory as well as protective eyewear for everyone in the room
I make a mix with Amosan powder and Hydrogen peroxide solution
The best sources of the H2O2 solutions are hairdressers who usually take
deliveries of 30, 60 or 90 vols solutions
The strongest you can get is 100 vols (about 33% solution ) but it is
very caustic - get your pharmacist to mix it fresh Keep it in a dark
brown bottle in the dark, date it and get fresh mix after 6 weeks
The peroxide will turn the fat/oils in you skins to soap instantly so
wear surgical gloves Failure of treatment can usually be traced to failure
to follow all of the above Re storage / disposal / fresh solution
I use a cotton pellet then ZnPo4 for sealing the cavity
Make sure you only go about 2 to 3mm subgingival in your canal preparation.
Have the patient ring you if they experience pain
Usually happens because you went deeper than 2 to 3 mm
I've had really dark teeth go whiter than the contralateral tooth within
Hope this helps
My father gave me the recipe he did endo for 56 referring dentists
- Jeremy Rourke
Jeremy, I respectfully disagree with you recommendation to use hydrogen
peroxide for internal bleaching procedure, as this agent can have some
serious side effects. A safer choice is the use of sodium perborate. A very
good review article on this topic has been published in the IEJ of May 2003,
I have listed their conclusion below here - Marga
Review of the current status of tooth whitening with the walking bleach
T. Attin, F. Paque¤ , F. Ajam & A . M. Lennon
Discoloured root-filled teeth can be successfully treated using the
walking bleach technique. Bleaching is performed by temporarily placing a
mixture of sodiumperborate-( tetrahydrate) and water into the pulp chamber.
This mixture releases H2O2 which is able to react with the staining
substances. In the case of severe and refractory discolouration, 3% H2O2
could be used instead of water. It is not advisable to use the
thermocatalytic methodwith heatingof a 30%H2O2 solution, as this procedure
increases the risko f external cervical resorption. For the same reason,
30% H2O2 should also not be used for the walking bleach technique. In order
to prevent seepage of H2O2 through dentine, it is necessary to place a
dense root filling and an additional cervical seal prior to starting the
walking bleach procedure. For long-term success, it seems to be important
to restore the access cavity with an adhesive filling, which prevents
leakage of bacteria and stains.
Marga....you were close on your citation...but see the one I did...
Madison and Walton did the study in Dogs...and I'm sure this review
article referenced that. I thought you should know so you get the source.
- Joey D
Jeremy, The only problem with using this technique is that it's associated
with increased resorption.
Walton did a study in Dogs that is considered a classic...while the abstract
is not quite perfect... they found increased resorption with heat OR
J Endod. 1990 Dec;16(12):570-4. Related Articles, Links
Cervical root resorption following bleaching of endodontically treated teeth.
Madison S, Walton R.
University of North Carolina School of Dentistry, Chapel Hill.
One year following root canal treatment and internal etching and bleaching
of anterior teeth in dogs, the animals were sacrificed and the teeth
prepared for stereomicroscopic or light microscopic examination. Evidence of
cervical root resorption and ankylosis was noted on several teeth. The
bleaching factors associated with the teeth exhibiting resorption were heat
with 30% hydrogen peroxide. Resorption was not related to walking bleach or
to internal etching alone. - Joey D